16/17/18 - Diuretics Flashcards
Which DIURETIC?
- *BUMETANIDE**
- *LOOP DIURETIC**
40-50x more potent than furosemide
Sulfonamide moiety
in furosemide and bumetanide also
provides weak CA inhibitory activity, thus
increase phosphate and bicarbonate excretion.
Which Diuretic causes this side effect?
“Contraction” Alkalosis
LOOP DIURETICS
Furosemide, Bumetanide, Torsemide, Ethacrinic Acid
Due to:
Significant diuresis can lead to hypovolemia ‐> stimulation of Aldosterone ‐> H+ excretion
Also:
HypoCalcemia*** // ***HypoMagnesemia
Ototoxicity // GOUT
Mild - HYPERglycemia / increase in Cholesterol / TG’s
Edema Treatment
Mainstay of therapy is:
NaCl RESTRICTION
diuretics will NOT work if the increased loss is REPLACED by MORE NACL INTAKE
Restriction depends on degree of edema:
SEVERE EDEMA: <1gm NaCl per day
- *Loop Diuretics are 1st line after**
- *daily dosing** –> increase dose or BID
Which DIURETIC?
Dichlorfenamide
META-disulfamoylbenzene derivatives
Carbonic Anhydrase Inhibitor
Which DIURETIC?
- *FUROSEMIDE**
- *LOOP DIURETIC**
Sulfonamide moiety
in furosemide and bumetanide also
provides weak CA inhibitory activity, thus
increase phosphate and bicarbonate excretion.
Which Diuretic?
- *Acetazolamide**
- *SIMPLE heterocyclic sulfonamides**
Carbonic Anhydrase Inhibitor
Which Diuretic causes this side effect?
METABOLIC ACIDOSIS
CAIs
Acetazolamide + Methazolamide (Simple)
Dichlorfenamide + Dorzolamide (meta)
HCO3 is indirectly REABSORBED by CA
VVV
Blocking CA –> less HCO3 reabsorbed // more EXCRETED
VVV
METABOLIC ACIDOSIS
Which Diuretic causes this side effect?
HypoCalcemia
LOOP DIURETICS
•Furosemide, Bumetanide, Torsemide, Ethacrinic Acid
Also:
HypoKalemia // HypoMagnesemia
Ototoxicity // GOUT // Contaction ALKAlosis
Mild - HYPERglycemia / increase in Cholesterol / TG’s
Also used for:
Severe HYPERcalcemia
but MAINLY EDEMA
not proven to be good for HYPERtension
Which Diuretic causes this side effect?
HypoNatremia
THIAZIDE DIURETICS
Also:
HYPERcalcemia
HypoKalemia*** / ***HypoMagnesemia / GOUT
and MILD:
HyperGlycemia // TG // Cholesterol
INEFFECTIVE @ CrCl <30 mL/min
need RENAL function
What occurs in the ASCENDING LIMB?
Urine Formation
- *“Dilution of Luminal Fluid”**
- water IMpermeable*
RE-absorption of NaCl
30% of filtered Na+ –> reenters
Para-cellular Transport
used to compensate for HIGH Na+
- *Symporter_ + _Antiporter**
- *ATPase**
Which Diuretic is indicated for:
DECREASED MORTALITY**in**HFrEF
heart failure w/ reduced ejection fraction
Aldosterone Antagonist
Spironolactone & Eplerenone
K+ sparing Diuretics, weak diuretic
Other indications:
Combo w/ HCTZ to prevent hypokalemia
Hepatic Cirrhosis w/ ascites
Resistant Hypertension
2-Step Concentration Process
of
Renal Tubular Secretion
(1 of 2 ways to enter into the luminal fluid, Glomerular Filtration is the other)
@PROXIMAL TUBULE
1) Active Secretion, interstitium –> proximal tubule
via OATS / OCTS
most diuretics are either weak organic acids or weak organic bases
important for GOUT –> URIC ACID competes with DIURETICS
2) Passive + Active Transport, Proximal Tubule –> Luminal Fluid
of diuretics
Which DIURETIC?
SORBITOL
Osmotic Diuretic
Which DIURETIC, based on MECHANISM OF ACTION?
- Inhibition of*
- *Renal Carbonic Anhydrase**
- decreases the:*
- *Sodium Carbonate Reabsorption**
Carbonic Anhydrase Inhibitors
CAI
Acetazolamide + Methazolamide
(Simple)
&
Dichlorfenamide + Dorzolamide
(meta)
Act on:
Proximal Tubule
Which DIURETIC?
MANNITOL
Isomer of SORBITOL
Osmotic Diuretics
Which DIURETIC?
- *TORSEMIDE**
- *Loop Diuretic**
- *sulfonylurea lacking an unsubstituted sulfamoyl group,**
- does not act at the proximal tubule*
- therefore does NOT increase phosphate or bicarbonate excretion.*
= no CA activity
Which Diuretic causes this side effect?
HYPERkalemia
K+ Sparing Diuretics
–Requires regular monitoring – can cause fatal arrhythmias
Risk increases greatly with CrCl < 50
Discontinue if K > 5.0 or CrCl < 30
Use in patients on dialysis is controversial in patients with HFrEF
Spironololactone also:
GYNECOMASTIA
What occurs in the COLLECTING DUCT?
Urine Formation
Re-Absorption of Water
- *Reabsorption & Secretion of**
- *Na / K / H / HCO3**
Na+/K+ ATPase
driving force for re-absprotion
- *What conditions cause a
- Diminished response to LOOP DIURETICS?***
Renal Insufficiency / Nephrotic Syndrome
Heart Failure / Cirrhosis
- may require
- HIGHER DOSES –> reach ceiling/max effect**
Ceiling dose:
- *80-160mg** for Furosemide
- *1-2 mg** for Bumetanide
How does the nephron REACT to HYPOVOLEMIA?
Reduced Plasma Volume or Dehydration
↓Renal Blood flow
↓GFR
↑Renin Secretion
↑Antidiuretic Hormone
increase in water RE-absorption
Which DIURETIC?
- *ETHCRYNIC ACID_ + _INDACRINONE**
- *Phenoxyacetic Acid-type High Ceiling Diuretics**
In addition to inhibit ATPase;
it also blocks the luminal Na+/K+/2Cl- co- transporter similar to furosemide
no sulfonamide group = does NOT inhibit CAI
Which DIURETIC?
- *EPLERENONE**
- *K+ Sparing Diuretic**
Aldosterone Receptor Agonist
Eplerenone, a newer aldosterone receptor antagonist with better ADH receptor selectivity than spironolactone.
What can NOT be taken with a LOOP DIURETIC?
THIAZIDE DIURETICS
CAN NOT BE TAKEN WITH LOOP DIURETICS
What group on Thiazide Diuretics is associated with:
HyperSensitivity Rxns / Drug-Induced Fever
Blood Dyscrasias / Interstitial Nephritis
Cross Sensitivity with CAI’s
+ loop diuretics or antibiotics with this group
SULFAMOYL MOIETY
SO2NH2
Thiazide Diuretics also have ADR of:
HypoKalemia
Which DIURETIC acts on:
EARLY DISTAL TUBULE
THIAZIDE DIURETICS